Merge pull request #1 from ga4gh/master

sync changes from ga4gh to dglazer
Update and rename methods.avdl to readmethods.avdl
Update and rename ga4gh.avdl to reads.avdl
Merge remote-tracking branch 'upstream/master' into rename-avdl
Merge pull request #43 from dglazer/rename-avdl

Rename avdl files to fit into a global API